CN113994604A

CN113994604A - Techniques to update beams in periodic transmissions

Info

Publication number: CN113994604A
Application number: CN202080043666.9A
Authority: CN
Inventors: 周彦; 骆涛; 张晓霞
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2019-06-21
Filing date: 2020-05-22
Publication date: 2022-01-28
Anticipated expiration: 2040-05-22
Also published as: US11638255B2; WO2020256891A1; US20200404639A1; CN113994604B; EP3987680A1

Abstract

Methods, systems, and devices for wireless communication are described. A User Equipment (UE) may determine that a first transmission on a first set of beams is unsuccessful and that a second transmission on a second set of beams is successful. The UE may identify a beam from the second set of beams based on a determination that the second transmission on the second set of beams is successful. The UE may send an indication of the identified beam from the second set of beams to the base station and communicate with the base station via the identified beam from the second set of beams.

Description

Techniques to update beams in periodic transmissions

Cross-referencing

This patent application claims the benefit of a U.S. provisional patent application No. 62/865,139 entitled "Techniques Updating Beams in personal Transmission", filed 2019, 21/6/2019 by Zhou et al; and U.S. patent application No. 16/880,232 entitled "Techniques Updating Beams in personal Transmissions", filed 21/5/2020 by Zhou et al, each of which is assigned to the assignee of the present application.

Technical Field

The following relates to, for example, wireless communications, and more particularly to techniques for updating beams in periodic transmissions.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be able to support communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems, such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-a) systems, or LTE-a Pro systems, and fifth generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems may employ techniques such as: code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communication system may include multiple base stations or network access nodes, each supporting communication for multiple communication devices (which may otherwise be referred to as User Equipment (UE)) simultaneously.

A wireless communication system may support a large number of UEs. In such applications, the base station or UE may utilize beamforming to improve signal quality and reliability. In some cases, transmissions between the base station and the UE may fail due to congestion or other reasons.

Disclosure of Invention

The described technology relates to improved methods, systems, devices, and apparatus that support techniques for updating beams in periodic transmissions. A User Equipment (UE) and a base station may communicate using periodic, beamformed transmissions. For example, the UE and the base station may be configured to communicate according to a semi-periodic scheduling (SPS) configuration, a Configured Grant (CG) configuration, or both. For SPS communications, a base station may be allocated periodic resources for downlink transmissions to one or more UEs. For CG communications, one or more UEs may each be allocated periodic resources for uplink transmissions to the base station. In some cases, the beams used for periodic communication may be updated. For example, if a periodic transmission from a base station using a first beam is unsuccessful, the active beam used for the downlink periodic transmission may be updated to another beam. For example, the strength of one or more beams may be measured, and the beams used for downlink periodic transmissions may be updated to a different beam that provides stronger signal strength at the UE.

Enhanced techniques for updating beams in periodic transmissions are described. For example, the UE may select a beam for beam update. This may enable the UE to quickly switch to a more reliable or higher quality beam. The UE may indicate the beam update explicitly or implicitly. For example, the UE may send a bit field explicitly indicating a beam update. Additionally or alternatively, the UE may transmit to the base station using uplink resources corresponding to the selected beam to implicitly indicate the beam update. Although techniques for SPS beam update and CG beam update are described herein, the following techniques may be applicable to other periodic communication schemes.

A method of wireless communication at a UE is described. The method may include: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second beam is successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams.

An apparatus for wireless communication at a UE is described. The apparatus may include: a processor, a memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by a processor to cause the apparatus to: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second set of beams is successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for: determining that a first transmission on a first set of beams is unsuccessful; determining that a second transmission on a second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second set of beams is successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second set of beams is successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission and the second transmission may be transmitted during a first data exchange period scheduled between the UE and the base station.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the communicating may further include: an operation, feature, unit or instruction for communicating with a base station via the identified beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period may be subsequent to the first data exchange period.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a beam for communication during the second data exchange period may be identified based on a most recently transmitted indication of the set of indications transmitted during the first data exchange.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: an operation, feature, means, or instruction for measuring a demodulation reference signal (DMRS) in a second transmission for each beam from a second set of beams, wherein the beam may be identified based on the measurement.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication comprises: a bit field indicating the identified beam from the second set of beams.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the bit field indicates a Transmission Configuration Indicator (TCI) state for each beam of the second set of beams.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the bit field indicates a spatial relationship information identifier for each beam of the second set of beams.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the indication may include: an operation, feature, unit or instruction for transmitting an indication on an uplink resource corresponding to the identified beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with the base station via the identified beam may include: operations, features, units or instructions for receiving a Physical Downlink Shared Channel (PDSCH) transmission from a base station on an identified beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission may be a downlink periodic transmission and the second transmission may be a retransmission of the first transmission.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication may be sent with an acknowledgement or negative acknowledgement for the second transmission.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission and the communication may be configured according to an SPS configuration.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, communicating with the base station via the identified beam may include operations, features, means, or instructions for transmitting a PUSCH transmission to the base station on the identified beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission may be an uplink transmission, the second transmission may be a downlink transmission carrying a demodulation reference signal (DMRS), and the indication may be sent with a retransmission of the first transmission.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission and the communication may be configured according to a CG configuration.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication is indicative of a beam scanning pattern.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the beam scan pattern includes at least a second set of beams, wherein the second transmission is transmitted on each beam of the beam scan pattern.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: operations, features, means, or instructions for transmitting a third transmission on the identified beam, wherein the first transmission may be configured according to a first periodic communication configuration and the third transmission may be configured according to a second periodic communication configuration.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: an operation, feature, unit or instruction to transmit a third transmission on the identified beam, wherein the third transmission may be in a transmission direction opposite to the first transmission.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: an operation, feature, unit or instruction to receive an indication from the base station to use the identified beam for the third transmission.

A method of wireless communication at a base station is described. The method may include: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam.

An apparatus for wireless communication at a base station is described. The apparatus may include: a processor, a memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by a processor to cause the apparatus to: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission and the second transmission may be transmitted during a scheduled data exchange period between the UE and the base station.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the communicating may further include: operations, features, units, or instructions for communicating with the UE via the indicated beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period may be subsequent to the first data exchange period.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication comprises a bit field indicating the indicated beam from the second set of beams.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the bit field indicates a TCI status for each beam of the second set of beams.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the indication may include: an operation, feature, unit or instruction for receiving an indication on an uplink resource corresponding to an indicated beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with the UE via the identified beam may include: operations, features, means, or instructions for transmitting a PDSCH transmission to a UE on an indicated beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication may be received with an acknowledgement or negative acknowledgement for the second transmission.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with the UE via the identified beam may include: operations, features, means, or instructions for receiving a PUSCH transmission from a UE on an indicated beam.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission may be an uplink transmission, the second transmission may be a downlink transmission carrying a demodulation reference signal (DMRS), and the indication may be received with a retransmission of the first transmission.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: operations, features, means, or instructions for transmitting a third transmission on the indicated beam, wherein the first transmission may be configured according to a first periodic communication configuration and the third transmission may be configured according to a second periodic communication configuration.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: operations, features, units or instructions for transmitting a third transmission on the indicated beam, wherein the third transmission may be in a transmission direction opposite to the first transmission.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include: an operation, feature, unit or instruction for sending an indication to the UE to use the indicated beam for a third transmission.

Drawings

Fig. 1 illustrates an example of a system for wireless communication that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 2 illustrates an example of a wireless communication system that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 3 illustrates an example of semi-persistent scheduling (SPS) beam updating that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 4 illustrates an example of a Configured Grant (CG) beam update that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 5 illustrates an example of a process flow for a technique that supports updating beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 6 and 7 show block diagrams of devices that support techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 8 illustrates a block diagram of a communication manager that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 9 shows a schematic diagram of a system including devices that support techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 10 and 11 show block diagrams of devices that support techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 12 illustrates a block diagram of a communication manager that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 13 shows a schematic diagram of a system including devices that support techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure.

Fig. 14-16 show flow diagrams illustrating methods of techniques to support updating beams in periodic transmissions, in accordance with aspects of the present disclosure.

Detailed Description

A User Equipment (UE) and a base station may communicate using periodic, beamformed transmissions. For example, the UE and the base station may be configured to communicate according to a semi-periodic scheduling (SPS) configuration, a Configured Grant (CG) configuration, or both. For SPS communications, a base station may be allocated periodic resources for downlink transmissions to one or more UEs. For CG communications, one or more UEs may each be allocated periodic resources for uplink transmissions to the base station. The wireless device may allocate periodic resources on a periodic basis. For example, resources for a base station to transmit an SPS message may be configured once per periodicity, where a duration of the periodicity may correspond to a periodicity of the SPS configuration. If the periodic transmission fails or is unsuccessful, there may be a period for retransmission attempts before the next period begins.

In some cases, the beams used for periodic communication may be updated. For example, if a periodic transmission from a base station using a first beam is unsuccessful, the active beam used for the downlink periodic transmission may be updated to another beam. Although the transmission from the base station using the first beam is unsuccessful, the first beam may still be used for communication (e.g., the beam may not have failed). The strength of one or more beams may be measured and the beams used for downlink periodic transmissions may be updated to a different beam that provides stronger signal strength at the UE.

In some wireless communication systems, the base station may select a beam update. For example, if the retransmission with the new beam is successful, the base station may indicate the selected beam to the UE. The base station may update the beam for the next period by transmitting reactivation Downlink Control Information (DCI) to the UE. The UE may decode the reactivation DCI, identify a beam indicated by the reactivation DCI, and use the indicated beam for periodic transmission in a next period. However, decoding the reactivation DCI in these systems may result in a delay in the beam update. For example, a UE may require several slots to decode. This may result in increased delay or reduced signal quality in the communication, as the UE may continue to use the previous, weaker beam until a new beam is identified.

Enhanced techniques for updating beams in periodic transmissions are described. For example, the UE may select the updated beam instead of waiting for the base station to transmit the reactivation DCI. This may enable the UE to switch to a more reliable or relatively higher quality beam faster than other techniques. The UE may indicate the beam update explicitly or implicitly. For example, the UE may send a bit field explicitly indicating a beam update. Additionally or alternatively, the UE may transmit to the base station using uplink resources corresponding to the selected beam to implicitly indicate the beam update. Although techniques for SPS beam update and CG beam update are described herein, the following techniques may be applicable to other periodic communication schemes.

Aspects of the present disclosure are initially described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to techniques for updating beams in periodic transmissions.

Fig. 1 illustrates an example of a wireless communication system 100 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The wireless communication system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-a) network, an LTE-a Pro network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low cost and low complexity devices.

The base station 105 may communicate wirelessly with the UE115 via one or more base station antennas. The base stations 105 described herein may include or may be referred to by those skilled in the art as base station transceivers, wireless base stations, access points, wireless transceivers, node B, eNodeB (eNB), next generation node bs or gigabit node bs (any of which may be referred to as a gNB), home node bs, home enodebs, or other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UEs 115 described herein may be capable of communicating with various types of base stations 105 and network devices, including macro enbs, small cell enbs, gnbs, relay base stations, and the like.

Each base station 105 may be associated with a geographic coverage area 110 in which communications with various UEs 115 are supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE115 may utilize one or more carriers. The communication links 125 shown in the wireless communication system 100 may include: uplink transmissions from the UE115 to the base station 105 or downlink transmissions from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

The geographic coverage area 110 for a base station 105 can be divided into sectors that form a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other type of cell, or various combinations thereof. In some examples, the base stations 105 may be mobile and thus provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE/LTE-a Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term "cell" refers to a logical communication entity for communication with the base station 105 (e.g., on a carrier) and may be associated with an identifier (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)) for distinguishing neighboring cells operating via the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine Type Communication (MTC), narrowband internet of things (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of devices. In some cases, the term "cell" may refer to a portion (e.g., a sector) of geographic coverage area 110 over which a logical entity operates.

The UEs 115 may be dispersed throughout the wireless communication system 100, and each UE115 may be stationary or mobile. The UE115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a user equipment, or some other suitable terminology, where a "device" may also be referred to as a unit, station, terminal, or client. The UE115 may also be a personal electronic device such as a cellular phone, a Personal Digital Assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, the UE115 may also be referred to as a Wireless Local Loop (WLL) station, an internet of things (IoT) device, an internet of everything (IoE) device, or an MTC device, among others, which may be implemented in various items such as appliances, vehicles, meters, and so forth.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M or MTC may refer to data communication techniques that allow devices to communicate with each other or with the base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application that may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, device monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based service charging.

Some UEs 115 may be configured to employ reduced power consumption modes of operation, such as half-duplex communications (e.g., modes that support unidirectional communication via transmission or reception but do not transmit and receive simultaneously). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for the UE115 include entering a power saving "deep sleep" mode when not engaged in active communications, or operating on a limited bandwidth (e.g., according to narrowband communications). In some cases, the UE115 may be designed to support critical functions (e.g., mission critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communication for these functions.

In some cases, the UE115 may also be able to communicate directly with other UEs 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs 115 in the group of UEs 115 communicating with D2D may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105 or otherwise unable to receive transmissions from the base station 105. In some cases, a group of UEs 115 communicating via D2D may utilize a one-to-many (1: M) system in which each UE115 transmits to every other UE115 in the group. In some examples, the base station 105 facilitates scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without the participation of base stations 105.

The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 over backhaul links 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other over backhaul links 134 (e.g., via X2, Xn, or other interfaces) directly (e.g., directly between base stations 105) or indirectly (e.g., via the core network 130).

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an Evolved Packet Core (EPC) that may include at least one Mobility Management Entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions (such as mobility, authentication, bearer management) for UEs 115 served by base stations 105 associated with the EPC. The user IP packets may be transported through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address assignment as well as other functions. The P-GW may be connected to a network operator IP service. The operator IP services may include access to the internet, intranets, IP Multimedia Subsystem (IMS) or Packet Switched (PS) streaming services.

At least some of the network devices, such as base stations 105, may include subcomponents, such as access network entities, which may be examples of Access Node Controllers (ANCs). Each access network entity may communicate with the UE115 through a number of other access network transport entities, which may be referred to as radio heads, intelligent radio heads, or transmit/receive points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., base station 105).

Wireless communication system 100 may operate using one or more frequency bands, such as in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). For example, the region from 300MHz to 3GHz is referred to as the Ultra High Frequency (UHF) region or decimeter band because wavelengths range from about one decimeter to one meter in length. UHF waves may be blocked or redirected by building and environmental features. However, the waves may penetrate a building sufficiently for the macro cell to provide service to the UE115 located indoors. UHF-wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100km) compared to transmission using smaller frequencies and longer waves in the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz.

The wireless communication system 100 may also operate in the ultra high frequency (SHF) region (also referred to as the centimeter band) using a frequency band from 3GHz to 30 GHz. SHF areas include frequency bands such as the 5GHz industrial, scientific, and medical (ISM) band that may be opportunistically used by devices that may be able to tolerate interference from other users.

The wireless communication system 100 may also operate in the Extremely High Frequency (EHF) region of the spectrum, e.g., from 30GHz to 300GHz (also referred to as the millimeter-wave band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE115 and the base station 105, and the EHF antenna of the respective device may be even smaller and spaced closer together than the UHF antenna. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the intended use of the frequency bands across these frequency regions may vary by country or regulatory body.

In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ Licensed Assisted Access (LAA), unlicensed radio frequency spectrum band radio access technology, or NR technology in an unlicensed band, such as the 5GHz ISM band. When operating in the unlicensed radio frequency spectrum band, wireless devices such as base stations 105 and UEs 115 may employ a Listen Before Talk (LBT) procedure to ensure that frequency channels are free before transmitting data. In some cases, operation in the unlicensed band may be configured based on carrier aggregation in conjunction with component carriers operating in the licensed band (e.g., LAA). Operation in the unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in the unlicensed spectrum may be based on Frequency Division Duplexing (FDD), Time Division Duplexing (TDD), or a combination of both.

In some examples, a base station 105 or UE115 may be equipped with multiple antennas that may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may be transmitted by the transmitting device via different antennas or different combinations of antennas, for example. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO) in which multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., base station 105, UE 115) to shape or steer an antenna beam (e.g., transmit beam, receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals transmitted via antenna elements in an antenna array such that signals propagating in one or more orientations relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals communicated via the antenna elements may include the transmitting device or the receiving device applying an amplitude offset and a phase offset to the signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a set of beamforming weights associated with an orientation (e.g., relative to an antenna array of a transmitting device or a receiving device, or relative to other orientations).

In one example, the base station 105 may use multiple antennas or antenna arrays for beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times in different directions by the base station 105, which may include the signals being transmitted according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or by a receiving device, such as the UE 115) a beam direction for subsequent transmission or reception by the base station 105.

Some signals, such as data signals associated with a receiving device, may be transmitted by the base station 105 in a single beam direction (e.g., a direction associated with a receiving device, such as the UE 115). In some examples, a beam direction associated with a transmission along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, the UE115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE115 may report to the base station 105 an indication of the signal it receives with the highest or otherwise acceptable signal quality. Although the techniques are described with reference to signals transmitted by the base station 105 in one or more directions, the UE115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting signals in a single direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., UE115, which may be an example of a device that receives mmW) may attempt multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may attempt multiple receive directions by: by receiving via different antenna sub-arrays, by processing received signals according to different antenna sub-arrays, by receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements in an antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements in an antenna array, either of which may be referred to as "listening" according to different receive beams or receive directions. In some examples, a receiving device (e.g., when receiving data signals) may use a single receive beam to receive along a single beam direction. A single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., based at least in part on a beam direction determined to have the highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based on listening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE115 may be located within one or more antenna arrays that may support MIMO operation, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with base stations 105 may be located in a variety of geographic locations. The base station 105 may have an antenna array that the base station 105 may use to support beamforming for communications with the UE115, the antenna array having a number of rows and columns of antenna ports. Likewise, the UE115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, the wireless communication system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. The Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate on logical channels. A Medium Access Control (MAC) layer may perform priority processing and multiplexing of logical channels to transport channels. The MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmissions at the MAC layer to improve link efficiency. In the control plane, a Radio Resource Control (RRC) protocol layer may provide for the establishment, configuration, and maintenance of RRC connections between UEs 115 and base stations 105 or core networks 130 supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels.

In some cases, the UE115 and the base station 105 may support retransmission of data to increase the likelihood of successfully receiving the data. HARQ feedback is one technique that improves the likelihood of correctly receiving data on the communication link 125. HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), Forward Error Correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). In poor radio conditions (e.g., low signal-to-noise ratio conditions), HARQ may improve throughput at the MAC layer. In some cases, a wireless device may support same slot HARQ feedback, where the device may provide HARQ feedback in a particular slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

The time interval in LTE or NR may be expressed in multiples of a basic time unit, which may for example refer to T_sA sample period of 1/30,720,000 seconds. The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as T_f＝307,200T_s. The radio frames may be identified by a System Frame Number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. The sub-frame may be further divided into 2 slots each having a duration of 0.5ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix pre-appended to each symbol period). Each symbol period may contain 2048 sample periods, excluding the cyclic prefix. In some cases, a subframe may be the smallest scheduling unit of the wireless communication system 100 and may be referred to as a Transmission Time Interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of shortened tti (sTTI) or in a selected component carrier using sTTI).

In some wireless communication systems, a slot may be further divided into a plurality of minislots containing one or more symbols. In some examples, a minislot or a symbol of a minislot may be a minimum unit of scheduling. For example, each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation. Further, some wireless communication systems may implement timeslot aggregation, where multiple timeslots or minislots are aggregated together and used for communication between the UE115 and the base station 105.

The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over the communication link 125. For example, the carrier of the communication link 125 may comprise a portion of a radio frequency spectrum band operating in accordance with a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. The carriers may be associated with predefined frequency channels (e.g., evolved universal mobile telecommunications system terrestrial radio access (E-UTRA) absolute radio frequency channel numbers (EARFCNs)) and may be located according to a channel raster for discovery by UEs 115. A carrier may be downlink or uplink (e.g., in FDD mode) or configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on a carrier may be composed of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as Orthogonal Frequency Division Multiplexing (OFDM) or discrete fourier transform spread OFDM (DFT-S-OFDM)).

The organization of the carriers may be different for different radio access technologies (e.g., LTE-A, LTE-A Pro, NR). For example, communications over carriers may be organized according to TTIs or slots, each of which may include user data and control information or signaling to support decoding of the user data. The carriers may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling for coordinating operation with respect to the carriers. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling for coordinating operations for other carriers.

The physical channels may be multiplexed on the carriers according to various techniques. The physical control channels and physical data channels may be multiplexed on the downlink carrier using, for example, Time Division Multiplexing (TDM) techniques, Frequency Division Multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, the control information sent in the physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

The carrier may be associated with a bandwidth of a radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as a carrier or "system bandwidth" of the wireless communication system 100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80MHz) for a carrier of the wireless access technology. In some examples, each served UE115 may be configured to operate on a portion of the carrier bandwidth or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type (e.g., an "in-band" deployment of narrowband protocol types) associated with a predefined portion or range within a carrier (e.g., a set of subcarriers or RBs).

In a system employing MCM technology, a resource element may include one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., order of modulation scheme). Thus, the more resource elements the UE115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communications with the UE 115.

Devices of the wireless communication system 100 (e.g., base stations 105 or UEs 115) may have a hardware configuration that supports communication over a carrier bandwidth or may be configurable to support communication over one carrier bandwidth of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE115 that supports simultaneous communication via carriers associated with more than one different carrier bandwidth.

The wireless communication system 100 may support communication with UEs 115 over multiple cells or carriers, which may be referred to as carrier aggregation or multi-carrier operation. The UE115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

In some cases, the wireless communication system 100 may utilize an enhanced component carrier (eCC). An eCC may be characterized by one or more characteristics, including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by a wide carrier bandwidth may include one or more segments that may be utilized by UEs 115 that cannot monitor the entire carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than other component carriers, which may include using a reduced symbol duration compared to the symbol duration of the other component carriers. Shorter symbol durations may be associated with increased spacing between adjacent subcarriers. A device utilizing an eCC (e.g., UE115 or base station 105) may transmit a wideband signal with a reduced symbol duration (e.g., 16.67 microseconds) (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80MHz, etc.). A TTI in an eCC may include one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

The wireless communication system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, or the like. Flexibility in eCC symbol duration and subcarrier spacing may allow eCC to be used across multiple spectra. In some examples, NR sharing spectrum may increase spectrum utilization and spectral efficiency, particularly through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

The UE115 and the base station 105 may communicate using periodic, beamformed transmissions. For example, the UE115 and the base station 105 may be configured to communicate according to an SPS configuration, a CG configuration, or both. For SPS communications, the base station 105 may be allocated periodic resources for downlink transmissions to one or more UEs 115. For CG communications, one or more UEs 115 may each be allocated periodic resources for uplink transmissions to the base station 105. In some cases, the beams used for periodic communication may be updated. For example, if a periodic transmission using a first beam from the base station 105 is unsuccessful, the active beam used for the downlink periodic transmission may be updated to another beam. In some cases, although the first beam is unsuccessful, the beam may be used for other communications (e.g., the beam may not fail). The strength of one or more beams may be measured and the beams used for downlink periodic transmissions may be updated to a different beam that provides stronger signal strength at the UE.

Enhanced techniques for updating beams in periodic transmissions are described. For example, the UE115 may select a beam for beam update. This may enable the UE115 to quickly switch to a more reliable or relatively higher quality beam. The UE115 may indicate the beam update explicitly or implicitly. For example, the UE115 may send a bit field explicitly indicating a beam update. Additionally or alternatively, the UE115 may transmit to the base station 105 using uplink resources corresponding to the selected beam to implicitly indicate the beam update. Although techniques for SPS beam update and CG beam update are described herein, the following techniques may be applicable to other periodic communication schemes.

Fig. 2 illustrates an example of a wireless communication system 200 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100. The wireless communication system 200 may include UEs 115 and base stations 105, and the UEs 115 and base stations 105 may be examples of the UEs 115 and base stations 105 as described with reference to fig. 1.

The UE115 and the base station 105 may communicate using beamformed transmissions. For example, the base station 105 may transmit or monitor directionally using one or more beams 205, and the UE115 may transmit or monitor directionally using beam 210. In some cases, beams such as beam 205 and beam 210 may include aspects of a transmit beam, a receive beam, or both.

The wireless communication system 200 may support configurations for periodic or semi-periodic communications. For example, the UE115 and the base station 105 may be configured to communicate according to an SPS configuration, a CG configuration, or both. For SPS communications, the base station 105 is allocated periodic resources for downlink transmissions to one or more UEs 115. For CG communications, one or more UEs 115 may each be allocated periodic resources for uplink transmissions to the base station 105. The wireless device may be allocated periodic resources based on the period 240. In some cases, the periodic resources for the base station 105 to send SPS messages may be configured once per period 240. For example, the period duration may correspond to a periodicity of the SPS configuration.

For example, the base station 105 may transmit a downlink shared channel message (e.g., a Physical Downlink Shared Channel (PDSCH) message 215) to the UE115 within the initial transmission period 230 of the cycle 240 (e.g., the first cycle 240-a). Additionally or alternatively, the UE115 may transmit an uplink shared channel message (e.g., a Physical Uplink Shared Channel (PUSCH) message 220) to the base station 105 within the initial transmission period 230 of the first cycle 240-a. During the initial transmission period 230 of the next period 240 (e.g., the second period 240-b), the UE115 and the base station 105 may again each be allocated resources for the PDSCH message 215 or the PUSCH message 220.

If the periodic transmission is not successfully received, there may be a period for retransmission attempts (e.g., retransmission period 235) before the next period 240 for the next periodic transmission. In some cases, a period 240 (e.g., one period) of the periodic communication configuration may include a period for initial transmission (e.g., an initial transmission period 230) and a retransmission period 235. For example, if the PUSCH message 220 is not successfully received at the base station 105, the base station 105 may report a negative acknowledgement message (NACK) for the unsuccessfully received PUSCH message 220. The UE115 may then have an opportunity to send a retransmission 245 of the PUSCH message 220 in the same period 240.

Periodic communications, such as SPS communications and CG communications, may apply beamforming techniques. In some examples, the base station 105 may transmit PDSCH messages towards the UE115 using beam 205-b according to SPS periodicity, and the UE115 may monitor transmissions using beam 210-b according to SPS periodicity.

In some cases, the beams used for periodic communication may be updated. For example, if a periodic transmission from the base station 105 using the first beam 205 is unsuccessful, the active beam used for the downlink periodic transmission may be updated to another beam. For example, the beam used for the downlink periodic transmission may be updated to a second beam that provides stronger signal strength at the UE 115.

In some wireless communication systems, the base station 105 may select beam updates for periodic communication with the UE 115. For example, if the retransmission with the new beam is successful, the base station 105 may update the beam for the next cycle by transmitting reactivation DCI to the UE 115. The reactivation DCI may indicate the selected beam to the UE 115. Then, the UE115 may decode the reactivation DCI, identify the beam indicated by the reactivation DCI, and use the indicated beam for periodic transmission in the next period 240. However, decoding the reactivation DCI in these systems may result in a delay in the beam update. For example, UE115 may require two or more slots to decode the reactivation DCI. The delay introduced by the UE115 decoding the reactivated DCI may result in increased latency or reduced signal quality in the communication because the UE115 may continue to use the previous beam until a new beam is identified.

The wireless communication system 200 may support enhanced techniques for updating beams in periodic transmissions. For example, rather than waiting for the base station 105 to transmit reactivation DCI, the UE115 may select an updated beam. This may enable the UE115 to switch to a more reliable or higher quality beam faster than other techniques. The UE115 may indicate the beam update explicitly or implicitly. For example, in some cases, the UE115 may send a bit field explicitly indicating a beam update. Additionally or alternatively, the UE115 may transmit to the base station 105 using an uplink channel corresponding to the updated beam to implicitly indicate the beam update. For example, the UE115 may use the updated beam to transmit an uplink message to the base station 105.

In some cases, the initial SPS transmission in period 240 may fail. The UE115 may indicate the failure and the base station 105 may retransmit the SPS transmission. The base station 105 may retransmit the SPS transmission using the set of beams, and the UE115 may perform beam measurements on each beam in the set of beams. In some cases, the base station 105 may be able to reuse the original beam for retransmission, as a transmission failure may not correspond to a beam failure. However, to increase the likelihood of successful transmission in a later SPS opportunity, the base station 105 may retransmit the SPS transmission using the set of beams.

The retransmission may be successful, and the UE115 may send an acknowledgement message (ACK) in response to the retransmission. The UE115 may send an indication of the highest quality beam with an ACK. Then, for the next period 240, the base station 105 may transmit another SPS transmission using the indicated beam. An example of SPS beam update is described in more detail with reference to fig. 3.

In another example, the initial CG transmission in period 240 may fail. The base station 105 may indicate the failure and send a control channel message to schedule CG retransmission. The base station 105 may transmit the control channel message using the beam set, and the UE115 may perform beam measurements on each beam in the beam set. The UE115 may identify the highest quality beam and retransmit the CG transmission using the identified beam. The retransmission may be successful and the UE115 may send a CG transmission using the identified beam during the next period. An example of CG beam update is described in more detail with reference to fig. 4.

In some cases, instead of indicating a single beam, the UE115 may indicate a beam scanning pattern for SPS transmissions, CG transmissions, or both in the next period 240. In some cases, the UE115 or base station 105 may be configured for multiple SPS or CG configurations. In some cases, beam updates based on one SPS or CG configuration may also apply to other SPS or CG configurations. Alternatively, in some examples, the beam update may be applied to an associated SP or CG configuration. In some cases, the base station 105 may indicate whether beam updates for one SPS or CG configuration may be applied (e.g., via DCI, MAC Control Element (CE), or RRC message) to other SPS or CG configurations.

In some cases, the beam scanning pattern may correspond to a plurality of beam pair links transmitted in a TDM-based scheme, an FDM-based scheme, or a Spatial Division Multiplexing (SDM) -based scheme, or any combination thereof. In some examples, the TDM-based beam scanning pattern may configure downlink data transmissions, uplink control transmissions for the downlink data transmissions, or uplink data transmissions via different beam pair links at different time allocations. In some cases, different time allocations correspond to different time slots or different minislots. In some examples, the FDM-based beam scanning pattern configures downlink data transmissions, uplink control transmissions for the downlink data transmissions, or uplink data transmissions via different beam pair links at different frequency allocations. In some cases, SDM-based beam sweep patterns simultaneously configure downlink data transmissions, uplink control transmissions for downlink data transmissions, or uplink data transmissions via different beam pair links at overlapping allocations of time and frequency. In some cases, each beam pair link of the plurality of beam pair links may be indicated by a Transmit Configuration Indicator (TCI) state or code point. In some cases, each beam pair link of the plurality of beam pair links may be indicated by a spatial relationship indication.

The UE115 may indicate a beam scanning pattern that may be used for uplink or downlink. The one or more beams indicated in the pattern may be time division multiplexed, frequency division multiplexed, or space division multiplexed. In some cases, the new beam indicated for the CG may also be used for SPS and vice versa. For example, the UE115 may be configured for both CG communication and SPS communication, and the UE115 may perform beam updating for CG communication as described herein. In the next period, the UE115 may use the updated beam for CG communication. In some cases, the UE115 may use the updated beam to select a new beam for SPS communication. This may be supported based on the UE115 having beam correspondence. For example, the updated beam used for CG communication may correspond to another beam (in some cases the same beam) that UE115 may use for SPS communication. In some cases, the base station 105 may indicate whether reusing beams for different periodic communication configurations is supported or enabled, such as via DCI, MAC-CE, or RRC messages.

If multiple new beam indications are received in the current period 240, the last indication received within the threshold of the end of the current period 240 may be used for the next period. For example, if the beam update indication is received within three time slots from the end of the first period, the beam update may not be used. However, the beam update indication received closest to but before the threshold may be applied for the next period.

Fig. 3 illustrates an example of SPS beam update 300 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. In some examples, SPS beam update 300 may implement aspects of wireless communication system 100 and wireless communication system 200.

The SPS beam update 300 includes a first period 305 and a second period 310, which first and

second periods

305 and 310 may be examples of SPS periods as described with reference to fig. 2. Each cycle may include an initial transmission period 315 and a retransmission period 320. For example, the first cycle 305 may include an initial transmission period 315-a and a retransmission period 320. The second periodicity 310 may include an initial transmission period 315-b and a retransmission period (not shown).

The base station 105 may be allocated periodic resources to transmit PDSCH messages 325 to one or more UEs 115 during the initial transmission period 315 of each period. For example, at 330, the base station 105 may transmit the PDSCH message 325-a to the UE115 using beam 335-a. The transmission on beam 335-a at 330 may fail or may be unsuccessful, which may trigger the SPS beam update procedure. The UE115 may also be configured with periodic resources, such as resources for CG transmission. At 345, the UE115 may send a PUSCH message 340-a carrying a NACK for the PDSCH message 325-a. In some cases, the UE115 may send a Physical Uplink Control Channel (PUCCH) message carrying NACK feedback for the unsuccessfully received PDSCH message 325.

During the retransmission time period 320, the base station 105 may retransmit the PDSCH message 325 for the UE115 using the set of beams 335 or the beams of the beam sweep. The set of beams 335 may include one or more beams. For example, the base station 105 may retransmit the PDSCH message 325 (e.g., as PDSCH message 325-b) using the set of beams 335 (including at least beam 335-b and beam 335-c). UE115 may monitor for retransmissions and perform beam measurements on the set of beams (e.g., including beam 335-b and beam 335-c). The UE115 may then identify a beam in the set of beams 335, such as the highest quality beam. At 355, the UE115 may send a PUCCH message 350 carrying ACK feedback to indicate that the SPS retransmission was successfully received.

In some cases, the UE115 may explicitly or directly indicate a new beam index in the PUCCH message 350 to update the SPS beam for the second periodicity 310. The new beam index may indicate (e.g., using a bit field) a TCI status corresponding to the best beam measured before the PUCCH message 350 is transmitted in the first period 305. For example, the UE115 may indicate a TCI status for the highest quality beam among the beams 335-a, 335-b, 335-c, and any other beams 335 measured during the first period 305 prior to transmitting the PUCCH message 350 at 355. The new beam may be based on measurements of DMRS for PDSCH messages utilizing different beams in the initial SPS transmission and any retransmissions. The UE115 may send the new beam index indication in the PUCCH message 350. In some cases, the UE115 may transmit the PUCCH message 350 using a beam corresponding to each beam in the beam sweep used to transmit the PDSCH message 325-b.

In some cases, the UE115 may implicitly indicate a new beam to update the SPS beam for the second periodicity 310. For example, each PDSCH transmitted on a beam of the beam sweep (e.g., transmitting PDSCH message 325-b as a retransmission) may have a corresponding PUCCH that uses the same beam. For an implicit indication, the UE115 may select a beam and send an ACK on the PUCCH resource corresponding to the selected beam. For example, the UE115 may send the ACK on the PUCCH resource corresponding to the selected beam and may not send the ACK on other PUCCH resources. The base station 105 may receive the ACK, identify the selected beam, and use the beam for SPS transmissions in the second period 310.

In some cases, such as shown in fig. 3, UE115 may determine that beam 335-c is the strongest of the measured beams. The UE115 may transmit a PUCCH message 350 carrying ACK feedback for the PDSCH message 325-b on PUCCH resources corresponding to beam 335-c. The base station 105 may receive the PUCCH message 350 on PUCCH resources corresponding to beam 335-c, identify beam 335-c as the selected beam, and use beam 335-c for SPS transmissions during the second period 310. For example, at 360, the base station 105 may transmit the PDSCH message 325-c to the UE115 using beam 335-c. At 365, the UE115 may send a PUSCH message 340-b carrying ACK feedback for the PDSCH message 325-c.

Fig. 4 illustrates an example of a CG beam update 400 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. In some examples, CG beam update 400 may implement aspects of wireless communication system 100 and wireless communication system 200.

The CG beam update 400 includes a first period 405 and a second period 410, and the first and

second periods

405 and 410 may be examples of SPS periods as described with reference to fig. 2. Each cycle may include an initial transmission period 415 and a retransmission period 420. For example, the first cycle 405 may include an initial transmission period 415-a and a retransmission period 420. The second periodicity 410 may include an initial transmission period 415-b and a retransmission period (not shown).

The UE115 may be periodically allocated resources to transmit a PUSCH message 430 to the base station 105 during an initial transmission period 415 of each cycle. The base station 105 may be allocated resources to receive PUSCH messages 430 from one or more UEs 115. The base station 105 may also be configured with periodic resources, such as resources for SPS transmissions. For example, the base station 105 may be allocated periodic resources in the initial transmission period 415 to send PDSCH messages 425-a and PDSCH messages 425-b to the UE 115.

At 445, the UE115 may transmit a PUSCH message 430-a on beam 435-a. However, transmission of the PUSCH message 430-a may be unsuccessful. During the retransmission period 420, the base station 105 may transmit a Physical Downlink Control Channel (PDCCH) message carrying NACK feedback on the beam set. For example, the base station 105 may transmit the PDCCH message 440 using the set of beams identified by the beam sweep. The beam sweep may identify, for example, at least beam 435-b and beam 435-c. In other examples, the beam sweep may include a different number of beams (e.g., one or more beams). The UE115 may measure DMRS for each beam used to transmit the PDCCH message 440. For example, the UE115 may measure the DMRS of the PDCCH using a different beam for scheduling CG retransmissions. The UE115 may then identify the best or highest quality beam of the set of beams used to transmit the PDCCH message 440.

At 450, the UE115 may send a retransmission of the PUSCH message 430 that was not successfully sent at 445. The PUSCH message 430-b retransmission may indicate the selected beam for CG beam update. In some cases, the UE115 may explicitly indicate the new beam index in the retransmission (e.g., PUSCH message 430-b). The new beam index may be indicated as the TCI status identifier corresponding to the best or strongest beam measured in the first period 405 prior to transmission of the PUSCH message 430-b at 450.

In some cases, UE115 may implicitly indicate a new beam to update the CG beam for second periodicity 410. For example, a PDCCH message scheduling each beam sweep of CG retransmissions may have one corresponding PUSCH resource. For an implicit indication, the UE115 may select a beam and send a retransmission on the PUSCH resources corresponding to the selected beam. For example, the UE115 may send a CG retransmission on a PUSCH resource corresponding to the selected beam and may not send a PUSCH retransmission on other PUSCH resources. The base station 105 may receive the PUSCH retransmission, identify the selected beam based on the PUSCH resources, and monitor the CG transmission in the second period 410 using the selected beam.

In some examples, as shown, UE115 may determine that beam 435-c is the strongest of the measured beams. UE115 may send a PUSCH retransmission on the PUSCH resources corresponding to beam 435-c. The base station 105 may receive a PUSCH retransmission on a PUSCH resource corresponding to beam 435-c, identify beam 435-c as the selected beam, and use beam 435-c for SPS transmissions during the second period 410. For example, at 455, the UE115 may transmit a PUSCH message 430-c to the base station 105 using beam 435-c.

Fig. 5 illustrates an example of a process flow 500 supporting techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. In some examples, the process flow 500 may implement aspects of the wireless communication system 100. Process flow 500 includes UE115 and base station 105.

At 505, the UE115 may send a first transmission to the base station 105, or the base station 105 may send the first transmission to the UE 115. In some examples, the UE115 may be configured with CG resources to periodically send PUSCH messages to the base station 105. Additionally or alternatively, the base station 105 may be configured with SPS resources to periodically send PDSCH messages to the UE 115. For CG communications, the UE115 may transmit a PUSCH message to the base station 105 on the periodic resources allocated to the UE115 in a first data exchange period scheduled between the UE115 and the base station 105. For SPS communications, the base station 105 may transmit PDSCH messages to the UE115 on the periodic resources allocated to the base station 105 in a first data exchange period scheduled between the UE115 and the base station 105.

In some cases, the UE115 may determine that the first transmission on the first set of beams was unsuccessful, e.g., if the first transmission is an SPS transmission. The UE115 may then send an uplink message carrying NACK feedback to the base station 105 at 510 to indicate that the first transmission failed. In some cases, the uplink message may be a PUCCH message or the uplink message may be a PUSCH message scheduled for CG communication.

The base station 105 may determine that the first transmission on the first set of beams was unsuccessful based on receiving the NACK feedback. At 515, the base station 105 may retransmit the SPS transmission on the set of beams as a second transmission. In some cases, the UE115 may determine that the second transmission on the second set of beams is successful. At 520, the UE115 may identify a beam from the second set of beams based on the determination that the second transmission on the second set of beams is successful. In some cases, the UE115 may measure the DMRS in the second transmission for each beam from the second set of beams. The UE115 may measure the DMRS for each transmission on each beam in the second set to identify a beam from the second set of beams.

At 525, the UE115 may transmit an indication of the identified beam from the second set of beams to the base station 105. In some cases, the UE115 may send an explicit indication of the identified beam. For example, the UE115 may transmit a bit field indicating the identified beam from the second set of beams. Alternatively, in some cases, the UE115 may implicitly indicate the identified beam. For example, the UE115 may send ACK/NACK feedback for SPS retransmissions on PUCCH resources associated with the identified beam. At 530, the UE115 and the base station 105 may communicate via the identified beam from the second set of beams. For example, the base station 105 may use the identified beam for another SPS transmission in a second period that is subsequent to the first period.

If the first transmission is a CG transmission, the base station 105 may send a PDCCH at 515 to schedule a retransmission of the CG transmission. At 515, the base station 105 may transmit a PDCCH message carrying DCI on the second set of beams to schedule CG retransmission. At 520, the UE115 may identify a beam from the second set of beams. In some cases, the UE115 may measure the DMRS for each PDCCH transmission on each beam in the second set of beams to identify the strongest beam.

At 525, the UE115 may transmit an indication of the identified beam from the second set of beams to the base station 105. In some cases, the indication may be sent with CG retransmission. In some cases, the UE115 may send an explicit indication of the identified beam. For example, the UE115 may transmit a bit field indicating the identified beam from the second set of beams. Alternatively, in some cases, the UE115 may implicitly indicate the identified beam. For example, the UE115 may send a CG retransmission on a PUSCH resource associated with the identified beam. At 530, the UE115 and the base station 105 may communicate via the identified beam from the second set of beams. For example, the UE115 may use the identified beam for another CG transmission in a second period after the first period.

Fig. 6 illustrates a block diagram 600 of a device 605 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 610 may receive information such as packets associated with various information channels (e.g., control channels, data channels, and information related to techniques for updating beams in periodic transmissions, etc.), user data, or control information. Information may be passed to other components of device 605. The receiver 610 may be an example of aspects of the transceiver 920 described with reference to fig. 9. Receiver 610 may utilize a single antenna or a group of antennas.

The communication manager 615 may perform the following operations: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second set of beams was successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams. The communication manager 615 may be an example of aspects of the communication manager 910 described herein.

The communication manager 615, or subcomponents thereof, may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615 or subcomponents thereof may be performed by a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

The communication manager 615, or subcomponents thereof, may be physically located at various locations, including being distributed such that some of the functionality is implemented at different physical locations by one or more physical components. In some examples, the communication manager 615, or subcomponents thereof, may be separate and distinct components in accordance with various aspects of the present disclosure. In some examples, the communication manager 615, or subcomponents thereof, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in this disclosure, or combinations thereof, in accordance with various aspects of the present disclosure.

The actions performed by the UE communication manager 615 as described herein may be implemented to obtain one or more potential advantages. An implementation may allow the UE115 to reduce latency by switching to an improved beam faster than waiting for and decoding a reactivation DCI transmission from the base station 105. The techniques described herein (such as supporting the UE115 to identify a new beam) may enable the UE115 to quickly switch to a higher quality beam. This may also improve communication quality because in situations where the UE may still be waiting to switch beams and experience a communication failure, the UE115 may use a higher quality beam faster, resulting in a successful transmission.

In some cases, the actions performed by UE communication manager 615 may enable UE115 to select an updated beam and indicate the beam update to the base station after an unsuccessful transmission. Such an indication may enable techniques for efficiently switching beams at the UE115, which may result in improved signal quality and more efficient communication (e.g., reduced latency in the system), among other advantages.

Based on implementing the indications as described herein, a processor of the UE115 or base station 105 (e.g., a processor that controls the receiver 610, the communication manager 615, the transmitter 620, or a combination thereof) may update the beams in periodic transmissions while ensuring relatively efficient communication. For example, the indication of beam updates described herein may utilize measurements of the strength of one or more beams used for periodic communications to determine updated beams, which may enable reduced signaling overhead and power savings, among other benefits.

Transmitter 620 may transmit signals generated by other components of device 605. In some examples, the transmitter 620 may be co-located with the receiver 610 in a transceiver component. For example, the transmitter 620 may be an example of aspects of the transceiver 920 as described with reference to fig. 9. The transmitter 620 may utilize a single antenna or a group of antennas.

Fig. 7 illustrates a block diagram 700 of a device 705 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of the device 605 or the UE115 as described herein. Apparatus 705 may include a receiver 710, a communication manager 715, and a transmitter 745. The device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 710 can receive information such as packets associated with various information channels (e.g., control channels, data channels, and information related to techniques for updating beams in periodic transmissions, etc.), user data, or control information. The information may be passed to other components of the device 705. Receiver 710 may be an example of aspects of transceiver 920 as described with reference to fig. 9. Receiver 710 can utilize a single antenna or a group of antennas.

The communication manager 715 may be an example of aspects of the communication manager 615 as described herein. The communication manager 715 may include a first transmission component 720, a second transmission component 725, a beam identification component 730, a beam indication component 735, and an updated beam communication component 740. The communication manager 715 may be an example of aspects of the communication manager 910 described herein.

First transmission component 720 may determine that the first transmission on the first set of beams was unsuccessful. The second transmission component 725 may determine that the second transmission on the second set of beams is successful. The beam identifying component 730 may identify a beam from the second set of beams based on a determination that the second transmission on the second set of beams is successful. Beam indicating component 735 may send an indication of the identified beam from the second set of beams to the base station. Updated beam communication component 740 may communicate with the base station via the identified beam from the second set of beams.

Based on the UE115 measuring the DMRS and identifying a new beam based on the DMRS measurements, a processor of the UE115 (e.g., the control receiver 710, the transmitter 740, or the transceiver 920 as described with reference to fig. 9) may efficiently adjust an antenna array or other radio frequency component to monitor or transmit using the identified beam. If the signal strength on the new beam is stronger, relatively less processing may be performed to receive and successfully decode the transmission using the new beam. This may result in improved performance of the processor of the UE 115.

A transmitter 745 may transmit signals generated by other components of the apparatus 705. In some examples, transmitter 745 may be co-located with receiver 710 in a transceiver component. For example, the transmitter 740 may be an example of aspects of the transceiver 920 described with reference to fig. 9. Transmitter 740 may utilize a single antenna or a group of antennas.

Fig. 8 illustrates a block diagram 800 of a communication manager 805 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The communication manager 805 may be an example of aspects of the communication manager 615, the communication manager 715, or the communication manager 910 described herein. Communications manager 805 may include a first transmission component 810, a second transmission component 815, a beam identification component 820, a beam indication component 825, an updated beam communications component 830, and a beam measurement component 835. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

First transmission component 810 may determine that the first transmission on the first set of beams was unsuccessful. The second transmission component 815 may determine that the second transmission on the second set of beams is successful. In some examples, the second transmission component 815 may communicate with the base station via the identified beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period is subsequent to the first data exchange period. In some cases, the first transmission and the second transmission are transmitted during a first data exchange period scheduled between the UE and the base station. In some cases, a beam for communication during the second data exchange period is identified based on a most recently transmitted indication of the set of indications transmitted during the first data exchange.

The beam identification component 820 can identify a beam from the second set of beams based on a determination that the second transmission on the second set of beams was successful. Beam indicating component 825 may transmit an indication of the identified beam from the second set of beams to the base station. In some examples, beam indicating component 825 may transmit the indication on uplink resources corresponding to the identified beam.

In some cases, the indication includes a bit field indicating the identified beam from the second set of beams. In some cases, the bit field indicates a TCI status for each beam in the second set of beams. In some cases, the bit field indicates a spatial relationship information identifier for each beam in the second set of beams. In some cases, the indication is to indicate a beam scanning pattern for the second data exchange period, the beam scanning pattern including at least a second set of beams, wherein the second transmission is transmitted on each beam of the beam scanning pattern.

Updated beam communication component 830 may communicate with the base station via the identified beam from the second set of beams. In some examples, updated beam communication component 830 may receive PDSCH transmissions from the base station on the identified beam. In some examples, updated beam communicating component 830 may send a PUSCH transmission to a base station on an identified beam. In some examples, updated beam communicating component 830 may transmit a third transmission on the identified beam, wherein the first transmission is configured according to the first periodic communication configuration and the third transmission is configured according to the second periodic communication configuration.

In some examples, updated beam communication component 830 may transmit a third transmission on the identified beam, wherein the third transmission is in a transmission direction opposite the first transmission. In some examples, updated beam communication component 830 may receive an indication from the base station to use the identified beam for the third transmission. In some cases, the first transmission is a downlink periodic transmission and the second transmission is a retransmission of the first transmission. In some cases, the indication is sent with an acknowledgement or negative acknowledgement for the second transmission. In some cases, the first transmission and the communication are configured according to an SPS configuration. In some cases, the first transmission is an uplink transmission, the second transmission is a downlink transmission carrying a DMRS, and the indication is sent with a retransmission of the first transmission. In some cases, the first transmission and communication are configured according to a CG configuration.

The beam measuring component 835 may measure the DMRS in the second transmission for each beam from the second set of beams, where the beam may be identified based on the measurements.

Fig. 9 shows a schematic diagram of a system 900 including a device 905 that supports techniques for updating beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 905 may be an example of a device 605, device 705, or UE115 or include components of a device 605, device 705, or UE115 as described herein. The device 905 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 910, an I/O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components may be in electronic communication via one or more buses, such as bus 945.

The communication manager 910 may perform the following operations: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; identifying a beam from the second set of beams based on a determination that the second transmission on the second set of beams was successful; transmitting, to the base station, an indication of the identified beam from the second set of beams; and communicating with the base station via the identified beam from the second set of beams.

The I/O controller 915 may manage input and output signals to the device 905. The I/O controller 915 may also manage peripheral devices that are not integrated into the device 905. In some cases, I/O controller 915 may represent a physical connection or port to an external peripheral device. In some cases, I/O controller 915 may utilize, for example

Or another known operating system. In other cases, I/O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, the I/O controller 915 may be implemented as part of a processor. In some cases, a user may interact with the device 905 via the I/O controller 915 or via hardware components controlled by the I/O controller 915.

The transceiver 920 may communicate bi-directionally via one or more antennas, wired links, or wireless links as described above. For example, the transceiver 920 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 920 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission and to demodulate packets received from the antenna.

In some cases, the wireless device may include a single antenna 925. However, in some cases, the device may have more than one antenna 925, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

The memory 930 may include a Random Access Memory (RAM) and a Read Only Memory (ROM). The memory 930 may store computer-readable, computer-executable code 935, the code 935 comprising instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 930 may contain a basic I/O system (BIOS) or the like that may control basic hardware or software operations such as interaction with peripheral components or devices.

Processor 940 may include intelligent hardware devices (e.g., general purpose processors, DSPs, Central Processing Units (CPUs), microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combinations thereof). In some cases, processor 940 may be configured to operate the memory array using a memory controller. In other cases, the memory controller may be integrated into processor 940. Processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause device 905 to perform various functions (e.g., functions or tasks to support techniques for updating beams in periodic transmissions).

Code 935 may include instructions to implement aspects of the disclosure, including instructions to support wireless communications. Code 935 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, code 935 may not be directly executable by processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

Fig. 10 shows a block diagram 1000 of a device 1005 supporting techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a base station 105 as described herein. The device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 1010 can receive information such as packets associated with various information channels (e.g., control channels, data channels, and information related to techniques for updating beams in periodic transmissions, etc.), user data, or control information. Information may be passed to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to fig. 13. Receiver 1010 may utilize a single antenna or a group of antennas.

The communication manager 1015 may perform the following operations: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam. The communication manager 1015 may be an example of aspects of the communication manager 1310 described herein.

The communication manager 1015 or subcomponents thereof may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 1015 or subcomponents thereof may be performed by a general purpose processor, a DSP, an Application Specific Integrated Circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

The communication manager 1015, or subcomponents thereof, may be physically located at various locations, including being distributed such that some of the functionality is implemented at different physical locations by one or more physical components. In some examples, the communication manager 1015 or subcomponents thereof may be separate and distinct components in accordance with various aspects of the present disclosure. In some examples, the communication manager 1015 or subcomponents thereof may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in this disclosure, or a combination thereof, in accordance with various aspects of the present disclosure.

The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with the receiver 1010 in a transceiver component. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 as described with reference to fig. 13. The transmitter 1020 may utilize a single antenna or a group of antennas.

Fig. 11 shows a block diagram 1100 of a device 1105 supporting techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of the device 1005 or the base station 105 as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1140. The device 1105 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 1110 can receive information such as packets associated with various information channels (e.g., control channels, data channels, and information related to techniques for updating beams in periodic transmissions, etc.), user data, or control information. The information may be passed to other components of the device 1105. The receiver 1110 may be an example of aspects of a transceiver 1320 as described with reference to fig. 13. Receiver 1110 can utilize a single antenna or a group of antennas.

The communication manager 1115 may be an example of aspects of the communication manager 1015 as described herein. The communication manager 1115 may include a first transmission component 1120, a second transmission component 1125, a beam indication component 1130, and an updated beam communication component 1135. The communication manager 1115 may be an example of aspects of the communication manager 1310 as described herein.

First transmission component 1120 may determine that the first transmission on the first set of beams was unsuccessful. The second transmission component 1125 may determine that the second transmission on the second set of beams is successful. Beam indicating component 1130 may receive an indication of a beam from the second set of beams from the UE. Updated beam communicating component 1135 may communicate with the UE via the indicated beam.

The transmitter 1140 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1140 may be co-located with the receiver 1110 in a transceiver component. For example, the transmitter 1140 may be an example of aspects of the transceiver 1320 as described with reference to fig. 13. Transmitter 1140 may utilize a single antenna or a group of antennas.

Fig. 12 illustrates a block diagram 1200 of a communication manager 1205 that supports techniques to update beams in periodic transmissions, in accordance with aspects of the present disclosure. The communication manager 1205 may be an example of aspects of the communication manager 1015, the communication manager 1115, or the communication manager 1310 described herein. The communication manager 1205 may include a first transmission component 1210, a second transmission component 1215, a beam indication component 1220, and an updated beam communication component 1225. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

First transmission component 1210 may determine that a first transmission on a first set of beams is unsuccessful. The second transmission component 1215 may determine that the second transmission on the second set of beams is successful. In some examples, the second transmitting component 1215 may communicate with the UE via the identified beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period is subsequent to the first data exchange period. In some cases, the first transmission and the second transmission are transmitted during a scheduled data exchange period between the UE and the base station. In some cases, a beam for communication during the second data exchange period is identified based on a most recently transmitted indication of the set of indications transmitted during the first data exchange.

Beam indicating component 1220 may receive an indication of a beam from the second set of beams from the UE. In some examples, beam indicating component 1220 may receive the indication on uplink resources corresponding to the identified beam. In some cases, the indication includes a bit field indicating the indicated beam from the second set of beams. In some cases, the bit field indicates a TCI status for each beam in the second set of beams. In some cases, the bit field indicates a spatial relationship information identifier for each beam in the second set of beams. In some cases, the indication is to indicate a beam scanning pattern for the second data exchange period, the beam scanning pattern including at least a second set of beams, wherein the second transmission is transmitted on each beam of the beam scanning pattern.

Updated beam communicating component 1225 may communicate with the UE via the indicated beam. In some examples, updated beam communicating component 1225 may send PDSCH transmissions to the UE on the indicated beams. In some examples, updated beam communicating component 1225 may receive a PUSCH transmission from a UE on the indicated beam.

In some examples, updated beam communicating component 1225 may transmit a third transmission on the indicated beam, where the first transmission is configured according to the first periodic communication configuration and the third transmission is configured according to the second periodic communication configuration. In some examples, updated beam communicating component 1225 may transmit a third transmission on the indicated beam, where the third transmission is in an opposite transmission direction from the first transmission. In some examples, updated beam communicating component 1225 may send an indication to the UE to use the indicated beam for the third transmission. In some cases, the first transmission is a downlink periodic transmission and the second transmission is a retransmission of the first transmission.

In some cases, the indication is sent with an acknowledgement or negative acknowledgement for the second transmission. In some cases, the first transmission and the communication are configured according to an SPS configuration. In some cases, the first transmission is an uplink transmission, the second transmission is a downlink transmission carrying a DMRS, and the indication is received with a retransmission of the first transmission. In some cases, the first transmission and communication are configured according to a CG configuration.

In some examples, beam correspondence component 1230 may transmit a third transmission on the indicated beam, where the third transmission is in an opposite transmission direction from the first transmission. In some examples, beam correspondence component 1230 may send an indication to the UE to use the indicated beam for the third transmission.

Fig. 13 shows a schematic diagram of a system 1300 including a device 1305 that supports techniques for updating beams in periodic transmissions, in accordance with aspects of the present disclosure. The device 1305 may be an example of or include a component of the device 1005, the device 1105, or the base station 105 as described herein. The device 1305 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, a memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses, such as bus 1350.

The communication manager 1310 may: determining that a first transmission on a first set of beams is unsuccessful; determining that the second transmission on the second set of beams is successful; receiving, from the UE, an indication of a beam from the second set of beams; and communicating with the UE via the indicated beam.

The network communication manager 1315 may manage (e.g., via one or more wired backhaul links) communication with the core network. For example, the network communication manager 1315 may manage the communication of data communications for client devices, such as one or more UEs 115.

The transceiver 1320 may communicate bi-directionally via one or more antennas, wired links, or wireless links as described above. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission and to demodulate packets received from the antenna.

In some cases, the wireless device may include a single antenna 1325. However, in some cases, the device may have more than one antenna 1325, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

The memory 1330 may include RAM, ROM, or a combination thereof. Memory 1330 may store computer-readable code 1335 comprising instructions that, when executed by a processor (e.g., processor 1340), cause the device to perform various functions described herein. In some cases, memory 1330 may contain a BIOS or the like that may control basic hardware or software operations such as interaction with peripheral components or devices.

Processor 1340 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combinations thereof). In some cases, processor 1340 may be configured to operate the memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1340. Processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1330) to cause device 1305 to perform various functions (e.g., functions or tasks that support techniques for updating beams in periodic transmissions).

The inter-station communication manager 1345 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communication manager 1345 may coordinate scheduling for transmissions to the UEs 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-station communication manager 1345 may provide an X2 interface within LTE/LTE-a wireless communication network technology to provide communication between base stations 105.

Code 1335 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. Code 1335 may be stored in a non-transitory computer readable medium, such as a system memory or other type of memory. In some cases, code 1335 may not be directly executable by processor 1340, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

Fig. 14 shows a flow diagram of a method 1400 that illustrates a technique that supports updating beams in periodic transmissions, in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by UE115 or components thereof as described herein. For example, the operations of method 1400 may be performed by a communication manager as described with reference to fig. 6-9. In some examples, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described below.

At 1405, the UE may determine that the first transmission on the first set of beams was unsuccessful. 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by the first transmission component as described with reference to fig. 6-9.

At 1410, the UE may determine that the second transmission on the second set of beams is successful. 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a second transmission component as described with reference to fig. 6-9.

At 1415, the UE may identify a beam from the second set of beams based on the determination that the second transmission on the second set of beams is successful. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operation of 1415 may be performed by a beam identification component as described with reference to fig. 6-9.

At 1420, the UE may transmit an indication of the identified beam from the second set of beams to the base station. 1420 operations may be performed according to methods described herein. In some examples, aspects of the operations of 1420 may be performed by a beam indicating component as described with reference to fig. 6-9.

At 1425, the UE may communicate with the base station via the identified beam from the second set of beams. The operations of 1425 may be performed in accordance with the methods described herein. In some examples, aspects of the operation of 1425 may be performed by the updated beam communication component as described with reference to fig. 6-9.

Fig. 15 shows a flow diagram of a method 1500 showing techniques to support updating beams in periodic transmissions, in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by UE115 or components thereof as described herein. For example, the operations of method 1500 may be performed by a communication manager as described with reference to fig. 6-9. In some examples, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described below.

At 1505, the UE may determine that the first transmission on the first set of beams was unsuccessful. 1505 may be performed in accordance with the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a first transmission component as described with reference to fig. 6-9.

At 1510, the UE may determine that the second transmission on the second set of beams is successful. 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a second transmission component as described with reference to fig. 6-9.

At 1515, the UE may measure a demodulation reference signal (DMRS) in the second transmission for each beam from the second set of beams, wherein the beam is identified based on the measurements. 1515 the operations may be performed according to the methods described herein. In some examples, aspects of the operation of 1515 may be performed by a beam measurement component as described with reference to fig. 6-9.

At 1520, the UE may identify a beam from the second set of beams based on the determination that the second transmission on the second set of beams is successful. 1520 may be performed according to methods described herein. In some examples, aspects of the operation of 1520 may be performed by a beam identification component as described with reference to fig. 6-9.

At 1525, the UE may send an indication of the identified beam from the second set of beams to the base station. 1525 the operations may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by a beam indicating component as described with reference to fig. 6-9.

At 1530, the UE can communicate with the base station via the identified beam from the second set of beams. 1530 operations may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be performed by an updated beam communication component as described with reference to fig. 6-9.

Fig. 16 shows a flow diagram of a method 1600 showing techniques to support updating beams in periodic transmissions, in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of method 1600 may be performed by a communication manager as described with reference to fig. 10-13. In some examples, the base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described below.

At 1605, the base station may determine that the first transmission on the first set of beams was unsuccessful. 1605 may be performed in accordance with the methods described herein. In some examples, aspects of the operations of 1605 may be performed by the first transmission component as described with reference to fig. 10-13.

At 1610, the base station may determine that the second transmission on the second set of beams is successful. 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a second transmission component as described with reference to fig. 10-13.

At 1615, the base station may receive an indication of a beam from the second set of beams from the UE. 1615 may be performed according to the methods described herein. In some examples, aspects of the operation of 1615 may be performed by a beam indicating component as described with reference to fig. 10-13.

At 1620, the base station may communicate with the UE via the indicated beam. 1620 may be performed according to methods described herein. In some examples, aspects of the operations of 1620 may be performed by an updated beam communication component as described with reference to fig. 10-13.

It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and the like. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. The IS-2000 version may be generally referred to as CDMA20001X, 1X, etc. IS-856(TIA-856) IS commonly referred to as CDMA20001 xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (W-CDMA) and other variants of CDMA. TDMA systems may implement wireless technologies such as global system for mobile communications (GSM).

The OFDMA system may implement wireless technologies such as Ultra Mobile Broadband (UMB), evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE)802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, flash OFDM, etc. UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS). LTE, LTE-A and LTE-A Pro are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization named "3 rd Generation partnership project" (3 GPP). CDMA2000 and UMB are described in documents from an organization named "3 rd generation partnership project 2" (3GPP 2). The techniques described herein may be used for the systems and wireless techniques mentioned herein as well as other systems and wireless techniques. Although aspects of the LTE, LTE-A, LTE-A Pro or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro or NR terminology may be used in much of the description, the techniques described herein may be applicable outside of LTE, LTE-A, LTE-A Pro or NR applications.

A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. Small cells may be associated with lower power base stations than macro cells, and small cells may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may include pico cells, femto cells, and macro cells according to various examples. For example, a pico cell may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in the home, etc.). The eNB for the macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communication using one or more component carriers.

The wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timings, and transmissions from different base stations may be misaligned in time. The techniques described herein may be used for synchronous operations or asynchronous operations.

The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and the following claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard-wired, or a combination of any of these. Features implementing functions may also be physically located at various locations, including being distributed such that some of the functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer data storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (eeprom), flash memory, Compact Disc (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes CD, laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, "or" (e.g., a list of items beginning with a phrase such as "at least one of or" one or more of) as used in a list of items indicates an inclusive list such that, for example, a list of at least one of A, B or C means a or B or C or AB or AC or BC or ABC (i.e., a and B and C). Further, as used herein, the phrase "based on" should not be construed as a reference to a closed condition set. For example, example steps described as "based on condition a" may be based on both condition a and condition B without departing from the scope of the present disclosure. In other words, the phrase "based on," as used herein, should be interpreted in the same manner as the phrase "based, at least in part, on.

In the drawings, similar components or features may have the same reference numerals. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description applies to any one of the similar components having the same first reference label irrespective of the second reference label or other subsequent reference labels.

The description set forth herein in connection with the drawings describes example configurations and is not intended to represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," and is not "preferred over" or "advantageous over" other examples. The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a User Equipment (UE), comprising:

determining that a first transmission on a first set of beams is unsuccessful;

determining that a second transmission on a second set of beams is successful;

identifying a beam from the second set of beams based at least in part on the determination that the second transmission on the second set of beams is successful;

transmitting, to a base station, an indication of the identified beam from the second set of beams; and

communicating with the base station via the identified beam from the second set of beams.

2. The method of claim 1, wherein the first transmission and the second transmission are transmitted during a first data exchange period scheduled between the UE and the base station.

3. The method of claim 2, wherein the communicating further comprises:

communicating with the base station via the identified beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period is subsequent to the first data exchange period.

4. The method of claim 3, wherein the beam for communication during the second data exchange period is identified based at least in part on a most recently transmitted indication of a plurality of indications transmitted during the first data exchange.

5. The method of claim 1, further comprising:

measuring a demodulation reference signal (DMRS) in the second transmission for each beam from the second set of beams, wherein the beam is identified based at least in part on the measurement.

6. The method of claim 1, wherein:

receiving a Physical Downlink Shared Channel (PDSCH) transmission from the base station on the identified beam.

7. The method of claim 6, wherein the first transmission is a downlink periodic transmission and the second transmission is a retransmission of the first transmission.

8. The method of claim 6, wherein the indication is sent with an acknowledgement or negative acknowledgement for the second transmission.

9. The method of claim 6, wherein the first transmission and the communication are configured according to a semi-persistent scheduling (SPS) configuration.

10. The method of claim 1, wherein:

transmitting a Physical Uplink Shared Channel (PUSCH) transmission to the base station on the identified beam, wherein the first transmission is an uplink transmission, the second transmission is a downlink transmission carrying a demodulation reference signal (DMRS), and the indication is transmitted with a retransmission of the first transmission.

11. The method of claim 10, wherein the first transmission and the communication are configured according to a Configured Grant (CG) configuration.

12. The method of claim 1, wherein the indication indicates a beam scanning pattern comprising at least the second set of beams, wherein the second transmission is transmitted on each beam of the beam scanning pattern.

13. The method of claim 1, further comprising:

transmitting a third transmission on the identified beam, wherein the third transmission is in an opposite transmission direction from the first transmission.

14. The method of claim 13, further comprising:

receiving an indication from the base station to use the identified beam for the third transmission.

15. The method of claim 1, wherein:

transmitting a third transmission on the identified beam, wherein the first transmission is configured according to a first periodic communication configuration and the third transmission is configured according to a second periodic communication configuration.

16. The method of claim 1, wherein the indication comprises a bit field indicating the identified beam from the second set of beams.

17. The method of claim 16, wherein the bit field indicates a Transmission Configuration Indicator (TCI) status for each beam of the second set of beams, a spatial relationship information identifier for each beam of the second set of beams, or both.

18. The method of claim 1, wherein transmitting the indication comprises:

transmitting the indication on an uplink resource corresponding to the identified beam.

19. A method for wireless communications at a base station, comprising:

determining that a first transmission on a first set of beams is unsuccessful;

determining that the second transmission on the second set of beams is successful;

receiving, from a User Equipment (UE), an indication of a beam from the second set of beams; and

communicating with the UE via the indicated beam.

20. The method of claim 19, wherein the first transmission and the second transmission are transmitted during a scheduled data exchange period between the UE and the base station.

21. The method of claim 20, wherein the communicating further comprises:

communicating with the UE via the indicated beam during a second data exchange period scheduled between the UE and the base station, wherein the second data exchange period is subsequent to the first data exchange period, and wherein the beam used for communication during the second data exchange period is identified based at least in part on a most recently transmitted indication of a plurality of indications transmitted during the first data exchange.

22. The method of claim 19, wherein communicating with the UE via the identified beam comprises:

transmitting a Physical Downlink Shared Channel (PDSCH) transmission to the UE on the indicated beam, wherein the first transmission is a downlink periodic transmission and the second transmission is a retransmission of the first transmission.

23. The method of claim 19, wherein communicating with the UE via the identified beam comprises:

receiving a Physical Uplink Shared Channel (PUSCH) transmission from the UE on the indicated beam.

24. The method of claim 19, wherein the indication indicates a beam scanning pattern comprising at least the second set of beams, wherein the second transmission is transmitted on each beam of the beam scanning pattern.

25. The method of claim 19, further comprising:

transmitting a third transmission on the indicated beam, wherein the first transmission is configured according to a first periodic communication configuration and the third transmission is configured according to a second periodic communication configuration.

26. The method of claim 19, further comprising:

transmitting a third transmission on the indicated beam, wherein the third transmission is in an opposite transmission direction from the first transmission; and

transmitting an indication to the UE to use the indicated beam for the third transmission.

27. The method of claim 19, wherein the indication comprises a bit field indicating the indicated beam from the second set of beams.

28. The method of claim 19, wherein receiving the indication comprises:

receiving the indication on an uplink resource corresponding to the indicated beam.

29. An apparatus for wireless communication at a User Equipment (UE), comprising:

means for determining that a first transmission on a first set of beams is unsuccessful;

means for determining that a second transmission on a second set of beams is successful;

means for identifying a beam from the second set of beams based at least in part on the determination that the second transmission on the second set of beams is successful;

means for transmitting, to a base station, an indication of the identified beam from the second set of beams; and

means for communicating with the base station via the identified beam from the second set of beams.

30. An apparatus for wireless communication at a base station, comprising:

means for receiving, from a User Equipment (UE), an indication of a beam from the second set of beams; and

means for communicating with the UE via the indicated beam.